EventMachine implements a single-threaded engine for arbitrary network communications. EventMachine wraps all interactions with sockets, allowing programs to concentrate on the implementation of network protocols. It can be used to create both network servers and clients.

Asciidoctor PDF is an extension for Asciidoctor that converts AsciiDoc documents to Portable Document Format (PDF) using the Prawn PDF library. It has features such as:

• Direct AsciiDoc to PDF conversion

• Configuration-driven theme (style and layout)

• Scalable Vector Graphics (SVG) support

• PDF document outline (i.e., bookmarks)

• Table of contents page(s)

• Document metadata (title, authors, subject, keywords, etc.)

• Internal cross reference links

• Syntax highlighting with Rouge, Pygments, or CodeRay

• Page numbering

• Customizable running content (header and footer)

• “Keep together” blocks (i.e., page breaks avoided in certain block content)

• Orphaned section titles avoided

• Autofit verbatim blocks (as permitted by base_font_size_min setting)

• Table border settings honored

• Font-based icons

• Custom TrueType (TTF) fonts

• Double-sided printing mode (margins alternate on recto and verso pages)

Markaby allows writing HTML packages in pure Ruby. This is similar to the functionality provided by ERB, but without the mixture of HTML and additional ERB syntax.

This package provides a collection of RuboCop cops to check for downstream compatibility issues in the Ruby code.

RubyRC4 is a pure Ruby implementation of the RC4 algorithm.

Gherkin-ruby is a Gherkin parser written in pure Ruby and less than 200 lines of code.

This package provides an automated way to track, and then re-run failed RSpec tests.

Introspection provides tools to inspect the hierarchy of method definitions on a Ruby object.

CiteProc is a citation processor interface and citation data API based on the CSL specifications. To actually process citations, a dedicated processor engine is required: a pure Ruby engine is available in the citeproc-ruby gem.

This library provides contracts for Ruby. A contract describes the correct inputs and output for a method, and will raise an error if a incorrect value is found.

Oedipus Lex is a lexer generator in the same family as Rexical and Rex. It is based primarily on generating code much like you would a hand-written lexer. It uses StrScanner within a multi-level case statement. As such, Oedipus matches on the first match, not the longest.

Tins is a Ruby library providing assorted tools.

Rubocop::AST extends ruby-parser with classes used by RuboCop to deal with Ruby's Abstract Syntax Tree (AST), in particular:

• RuboCop::AST::Node

• RuboCop::AST::NodePattern

Given is an RSpec extension that allows the use of Given/When/Then terminology when defining specifications, in a way similar to the Cucumber Gherkin language.

This package provides the Minitest::Retry class, which extends Minitest to allow retrying tests when they fail.

This library allows reading and writing RPM packages. It is used by the fpm tool. It is written in pure Ruby because librpm is not available on all systems and requires many dependencies.

Tilt is a thin interface over a number of different Ruby template engines in an attempt to make their usage as generic as possible.

This gem contains the core algorithms and classes used for doing basic programming with RDF data, implemented in pure Ruby.

This package provides a library to help create value objects without the pain of Ruby's Struct (or its setters).

Concurrent Ruby includes concurrency tools such as agents, futures, promises, thread pools, actors, supervisors, and more. It is inspired by Erlang, Clojure, Go, JavaScript, actors, and classic concurrency patterns.

This package provides Ruby FFI bindings to the Networking and Cryptography (NaCl) library, also known as libsodium. This provides a high-level toolkit for building cryptographic systems and protocols.

Asciidoctor generates single-page documents. This extension splits documents up into multiple HTML pages according to their headings, with configurable levels.

This gem extends ruby-rdf with several common RDF vocabularies.

Bump provides commands to manage Rubygem versioning, updating to the next patch version for example.